Introduction to powder metallurgy products:
Powder metallurgy products are various types of products manufactured by forming and sintering process, using metal powder (iron powder, copper powder, stainless steel powder, etc.) or mixture of metal powder and non-metallic powder as raw materials.
Production process of powder metallurgy products:
(1) The production process of powder includes the steps of powder preparation, powder mixing, etc. In order to improve the formability and plasticity of the powder, plasticizers such as gasoline, rubber or paraffin are usually added.
(2) The powder is pressed to the required shape under the pressure of 500~600MPa.
(3) Sintering is carried out in a high temperature furnace or a vacuum furnace with a protective atmosphere. Sintering is different from metal melting. At least one element is still in solid state during sintering. During sintering, the powder particles become metallurgical products with certain porosity through a series of physical and chemical processes such as diffusion, recrystallization, fusion welding, combination, dissolution, etc.
(4) After treatment, generally, sintered parts can be used directly. But for some parts with high dimensional accuracy, high hardness and wear resistance, post sintering treatment is also required. Post treatment includes fine pressing, rolling, extrusion, quenching, surface quenching, oil immersion, and infiltration.